I still fell weak.

Even i am in Dragon Spyre(By the way, is the word "Spyre" Really a real word?), I am level 46, i still fell weak to monsters such as dragons or soldiers. Is that normal cause the monsters are too powerful or because i am too weak?

Give it time, DS fighting is a little different from other worlds, with stronger bosses and street battles. Hitting level 48 won't hurt, but you just need time to adjust to your new environment, when you do, you won't feel weak you will be prepared.